六星瓢虫对柑橘木虱若虫的捕食功能反应及捕食偏好

Predatory functional response and predation preference of Oenopia formosana for the nymphs of Asian citrus psyllid Diaphorina citri

【目的】为探究六星瓢虫Oenopia formosana对柑橘木虱Diaphorina citri的生物防控潜能,以及存在萝卜蚜Lipaphis erysimi时的捕食偏好。【方法】在实验室条件下测定六星瓢虫1-4龄幼虫和成虫对柑橘木虱5龄若虫的捕食功能和寻找效应,以及同时存在柑橘木虱和萝卜蚜时六星瓢虫的捕食选择。【结果】各虫态的六星瓢虫均能捕食5龄的柑橘木虱若虫,捕食功能反应均符合HollingⅡ模型。六星瓢虫1-4龄幼虫和成虫对柑橘木虱5龄若虫的瞬时攻击率分别为0.279、0.430、0.689、0.829和0.695,理论日最大捕食量分别为29.155、32.895、46.512、58.824和79.365头,处理时间分别为0.034、0.030、0.022、0.017和0.013d,控害效能分别为8.148、14.131、32.048、48.747和55.130。六星瓢虫的各个龄期对5龄的柑橘木虱若虫的搜寻效应均随着猎物密度的变大而降低,4龄六星瓢虫幼虫的搜寻效应随猎物密度增加下降趋势最大,当柑橘木虱5龄若虫的低密度存在时,4龄幼虫的搜寻效应高于其他龄期的六星瓢虫。存在柑橘木虱与萝卜蚜两种捕食对象的情况下,六星瓢虫成虫表现出对柑橘木虱有捕食偏好。【结论】各虫态的六星瓢虫对5龄的柑橘木虱若虫均具有一定的控害效果,其4龄幼虫和成虫对柑橘木虱5龄若虫的防控效果比较好,推荐用于柑橘木虱的生物防治。

[Aim]To investigate the potential of Oenopia formosana as a biological control for the Asian citrus psyllid Diaphorina citri,and determine if they prefer D.citri to Lipaphis erysimi.[Methods]The predatory functional response,search efficiency and preference of O.formosana for the 1st,2nd,3rd and 4th instar nymphs,and adult stages up to the 5th instar nymph of D.citri,were studied under laboratory conditions.[Results]All stages of O.formosana preyed on the 5th instar nymph of D.citri,and the functional response of all stages fitted the HollingⅡmodel.The instant attack rates of O.formosana 1st to 4th instar nymphs and adults towards D.citri were 0.279,0.430,0.689,0.829 and 0.695,respectively,Maximum daily predation rates were 29.155,32.895,46.512,58.824 and 79.365 prey,respectively,and the predation capacity was 8.148,14.131,32.048,48.747 and 55.130,respectively,and the processing times were 0.034,0.030,0.022,0.017 and 0.013 d,respectively.The search effort of all stages decreased with increasing density of D.citri,showing the most obvious decline in the 4th instar.At low D.citri densities,4th instar O.formosana had the highest search effort.When 5th instar nymphs of D.citri and adult L.erysimi were both present,adult O.formosana preferred to prey on D.citri.[Conclusion]All life-stages of O.formosana have the potential to control 5th instar D.citri nymphs,but 4th instar and adults are more likely to be effective biological control agents for D.citri than 1st to 3rd instar nymphs.